1. Field of the Invention OF THE INVENTION
This invention relates to an automatic rhythm programmer used for actuating electrical musical voice generators to provide musical instrument rhythm sounds according to predetermined rhythmic patterns.
2. Description of the Prior Art
There are a number of automatic rhythm programmers in use which provide electrical pulses for actuating a group of electrical musical voice generators according to repeated preselected rhythmic patterns, such as the waltz, dixieland, march, etc. Such voice generators comprise known electrical circuits which, when pulsed, produce, in conjunction with an audio output system, various untuned musical sounds of the type usually associated with the percussion section of an orchestra which are useful to provide rhythm background accompaniment for an electrical musical instrument such as an electronic organ. See, for example, the following U.S. Pat. Nos. which are believed to be representative of the current state of the art: Richard H. Campbell, Jr. 3,358,068 Donald M. Park et al. 3,383,452 Donald M. Park RE. 26,521 Alfred B. Freeman 3,548,065 Alfred B. Freeman 3,553,334 Harold O. Schwartz 3,585,891
The devices disclosed in all of the above patents produce actuating pulses for voice generators according to any selected one of a number of basic rhythmic patterns which are continuously repeated without any variation. However, such basic patterns sound monotonous after being played for any length of time. The present invention eliminates such monotony by providing a method for automatically modifying or cancelling actuating pulses for certain non-essential voice generators periodically while maintaining the basic rhythmic patterns.
The manual or automatic introduction of variations into any of the basic rhythmic patterns could not be economically provided using the systems of any of the above patents. The Campbell, Park and Freeman patents teach means for generating and supplying pulses to a logic matrix which combines the pulses according to different rhythmic patterns and has output terminals which are selectively switched to certain voice generators according to the desired rhythmic pattern; since the same matrix is used for all of the rhythmic patterns, a method for selectively switching the matrix to the voice generators for each combination of a basic rhythmic pattern and one or more pattern variations is not economically possible with these systems.
The Schwartz system, while designed to reduce the cost and size of rhythm programmers, contains a complex logic circuit using solid-state integrated circuit components which, nevertheless, requires 14 integrated circuit chips to provide only 5 basic rhythmic patterns, with no provision for pattern variation.